1. Field of the Invention
The invention relates to a method for determining an indicator of the stresses to which a vehicle tire is subjected during a given period. In particular, the invention relates to determining an indicator of the stresses to which the tire of a construction vehicle, such as a dumper, is subjected during a duration of use, a construction vehicle being, for example, a vehicle which is intended to bear heavy loads, and which operates in quarries and/or mines.
2. Description of Related Art
A dumper typically comprises a front steered axle having two steered wheels and a rear axle, which is most frequently rigid, having four driving wheels distributed in pairs on each side. An axle is defined as an assembly of the elements enabling the fixed structure of the vehicle to be connected to the ground.
In the case of construction vehicles, particularly those intended for use in mines or quarries for transporting loads, the problems of access and demands of production are leading the manufacturers of these vehicles to increase their loading capacity. It follows that the vehicles are becoming larger and therefore themselves are becoming heavier and can transport greater loads. The current weights of these vehicles may be as much as several hundred tons, and the same applies to the load to be transported; the overall weight may be as much as 600 tons. Since the loading capacity of the vehicle is directly linked to that of the tires, the design of the tires must be adapted to these increasing weights and loads in order to provide tires capable of withstanding the stresses of use.
The dimensions of these tires are therefore large. Consequently, the dimensions of the wheels are also large and the rigidity of the bottom zones of the tires requires the wheels to be made in several parts to allow mounting of the tire on a rim. The operations involved in mounting and demounting the tires in the event of replacement or maintenance are long and tedious. The number of clamping parts which have to be handled during these operations may be greater than 200, and very high levels of clamping torque for these parts are associated therewith. The time taken for these operations is consequently long and therefore detrimental to the productivity sought during working of the mines.
Since current demand is still aimed at increasing the loading capacity of such construction vehicles, the different parameters listed previously have led tire designers to optimize the tires by taking into account the particular use thereof. The inventors therefore set themselves the task of responding to the demand from users, who wish to see a further increase in the loading capacity of the load-carrying machinery, in particular that used in mines, with the performance of the tires being optimized for such applications.